Top-seeded Novak Djokovic has advanced to his fourth straight U.S. Open final,
overcoming the loss of a 21-minute game in the fifth set to defeat Stanislas
Wawrinka 2-6, 7-6 (4), 3-6, 6-3, 6-4.

Those who have been carping about Andy Murray’s quarter-final exit from the US Open should look at Wawrinka’s agonisingly narrow defeat and understand just how hard it is to reach the finals of these events.

Having already beaten successive top five opponents, including Murray in straight sets on Thursday, Wawrinka came out swinging lustily again against Novak Djokovic. He had taken a lead of two sets to one when a muscle tweaked high up in his right thigh.

Wawrinka left the court to have the leg taped, and swigged some painkillers. They kicked in well enough for him to compete bravely all the way through the final stages. But you cannot afford even a minor handicap against an opponent as implacable as Djokovic. He is the bionic man of sport, and he is through to the final.

Early in the deciding set, the crowd rose to deliver a standing ovation. That was after the penultimate point of an absurdly tense game in which Wawrinka had saved no fewer than five break points.

The Swiss finally held with an ace after 21 minutes and 29 points, which made this single game longer and more competitive than many of Serena Williams’s recent sets.

“I guess everyone was thinking ‘Whoever wins this game is going to win the match,’” said Djokovic afterwards. “So after he won the game, I thought to myself ‘OK, I’m going to fight against those odds’.”

Earlier, Djokovic was simply not himself in a curious first set in which he was broken three times. Like Murray in the previous round, he looked flat and nervous, as if the instincts which normally fuel his adamantine game were malfunctioning.

Yet the difference was that, when Murray tried to flick the switch that turns on the afterburners, the engines refused to fire.

Whereas Djokovic eventually settled into the match and began pressurising Wawrinka with his court coverage and resilience. You could call it passive-aggressive play, because the world No1 was not generally going for the winners. Rather, he was absorbing his opponents’ best shots and gradually wearing him down.

“I think it was obvious that Stan played more aggressive and he played the better tennis overall and I was just trying to hang in there,” Djokovic said. “I’m just so fortunate to be able to play my best tennis when I needed to.”

Wawrinka looked close to tears in his on-court interview but finally managed to squeeze out an X-rated comment which the broadcasters had to apologise for. “He’s ----ing strong so congrats Nole. But for me I give everything, I fight until the end and the crowd – it was an amazing experience.”

That is the trouble with being a world-class tennis player in the modern era. Eight years ago, Andre Agassi made the final of this tournament without beating anybody ranked higher than Tomas Berdych, then a promising 19-year-old who stood at No. 34 in the world.

But those were the days before Roger Federer had changed the whole rhythm of the sport by going to the last four of every single slam, every single year.

His patterns have since been imitated by his two closest peers – Rafael Nadal and Novak Djokovic – so that there is rarely any such thing as a free lunch anymore, particularly in the hard-court events. You have to beat the best in the world, and keep beating then, set after set after set. This explains why modern slam winners tend to come from a small group of names.

After Murray’s defeat at the gifted hands of Wawrinka, he was asked whether he saw the Swiss as a genuine contender for the title. “I don't know,” he said. “I know how hard they are to win. I have reached quite a few semis and finals before I did it. You'll find out in the next few days I guess.”

And so we did after Saturday’s thrilling five-setter, a match that was comfortably the highlight of the tournament so far.

Apart from the drama of the match itself, Wawrinka produced one of the best racket-smashes of the year – bending the frame against his knee until it resembled a piece of modern art – which earned him a point penalty, while Djokovic was warned in the second set for receiving coaching from his players’ box.

It was not Wawrinka’s tennis that fell short, but mentally and physically he is not used to trading with these sort of players for round after round. So for the second time this year, he fell to Djokovic in five sets on a hard-court slam. No wonder he turned the airwaves blue afterwards.